specific wavelength of ultraviolet (UV) light is not only extremely effective at killing the virus which causes COVID-19, but is also safer for use in public spaces, finds new University of Colorado Boulder research.
The study, published this month in Applied and Environmental Microbiology, is the first to comprehensively analyze the effects of different wavelengths of UV light on SARS-CoV-2 and other respiratory viruses, including the only wavelength safer for living beings to be exposed to without protection.
The findings, which the authors refer to as a "game changer" for UV light use, could lead to new affordable, safe and highly effective systems for reducing viral spread in crowded public spaces like airports and concert venues.
"Of almost every pathogen we have ever studied, this virus is one of the easiest, by far, to kill with UV light," said senior author Karl Linden, professor of environmental engineering. "It takes a very low dose. This indicates that UV technology could be a really good solution for protecting public spaces."
Päike kiirgab loomulikult UV-valgust ja enamik vorme on kahjulikud nii elusolenditele -- kui ka mikroorganismidele, näiteks viirustele. See valgus võib imenduda organismi genoomi, siduda sellesse sõlme ja takistada selle paljunemist. Need päikese kahjulikud lainepikkused aga filtreeritakse osoonikihi poolt välja enne, kui need jõuavad Maa pinnale.
Mõned levinud tooted, nagu luminofoorlambid, kasutavad inimese-konstrueeritud UV-valgust, kuid sees olev valge fosforkate kaitseb inimesi UV-kiirte eest.
"When we take that coating off, we can emit those wavelengths, and they can be harmful for our skin and our eyes -- but they can also kill pathogens," said Linden.
Haiglad kasutavad juba UV-valgustehnoloogiat pindade desinfitseerimiseks ruumides, kus neis ei viibi inimesi, kasutades roboteid, mis võivad kasutuskordade vahel operatsiooni- ja patsientide tubades UV-valgust paista.
And many gadgets on the market today clean everything from cell phones to water bottles with UV light. But safety protocols are still being developed by the FDA and EPA. Linden cautions against using any personal or "germicidal" devices in which a person is exposed to UV light.
Ta ütles, et uued leiud on ainulaadsed, kuna need on inimestele suhteliselt ohutu ja viirustele, eriti COVID-19 põhjustavatele viirustele kahjulike UV-valguse vahel.
"This can be a game changer for the public use of UV light in indoor spaces," said Linden.
Surm kokkupuute tõttu
Uuringu jaoks võrdlesid Linden ja tema meeskond erinevaid UV-lainepikkusi{0}}kõrvuti-, kasutades UV-valgustööstuses välja töötatud standardmeetodeid.
"We thought, let's come together and make a definitive statement on what UV exposure is required to kill off SARS-CoV-2," said Linden. "We wanted to make sure that if UV light is being used to control disease, you're delivering the right dose that's protective of human health and human skin, but also going to be killing off these pathogens."
The opportunity to do this kind of work is rare, as there are extremely rigorous safety standards required to work with SARS-CoV-2. So Linden and Ben Ma, postdoctoral researcher in Linden's research group, collaborated with virologist Charles Gerba at the University of Arizona, at a lab cleared to work with the virus and its variants.
The researchers found that while the virus was quite susceptible to UV light in general, a specific wavelength of Far ultraviolet-C, at 222 nanometers, was particularly effective. Created by what's known as a krypton chloride excimer lamp, fueled by molecules moving between different states of energy, this wavelength is very high energy. Therefore, it's able to inflict greater viral protein and nucleic acid damage to the virus compared to other UV-C devices, as well as be blocked by the very top layers of human skin and eyes -- meaning that it has limited to no detrimental health effects at doses that are capable of killing off viruses.
"Not only is it safe, it's also the most effective," said Linden.
UV-desinfitseerimise roll tänapäeval
UV light in various forms has been used widely since the early 20th century to disinfect water, air and surfaces. As early as the 1940s, it was used to reduce the transmission of tuberculosis in hospitals and classrooms, by shining the light at the ceiling to disinfect air as it circulated throughout the room. Today, it's used not only in hospitals, but in some public bathrooms and airplanes when there are no people in those spaces.
In a recent White Paper published by the International UV Association, "Far UV-C Radiation: Current State-of Knowledge," which accompanies the new study, Linden and co-authors argue that this safer wavelength of Far UV-C light could serve as a key mitigation measure against the current and future pandemics, in addition to improved ventilation, mask wearing and vaccination.
Linden kujutab ette süsteeme, mis võiksid siseruumides tsükliliselt sisse ja välja lülitada, et rutiinselt õhku ja pindu puhastada, või luua pideva nähtamatu barjääri õpetajate ja õpilaste, klientide ja teenindustöötajate ning inimeste vahel ruumides, kus sotsiaalne distantseerumine pole võimalik. desinfitseerida õhku.
UV light disinfection can even rival the positive effects of improved indoor ventilation by providing the equivalent protection of increased air changes per hour within a room. It's also much cheaper to install UV lights than to upgrade an entire HVAC system.
"There is an opportunity here to save money and energy while protecting public health in the same way. It's really exciting," said Linden.
Selle väljaande lisaautorite hulka kuuluvad: Ben Ma CU Boulderist; Patricia Gundy ja Charles Gerba Arizona ülikoolist; ja Mark Sobsey Põhja-Carolina ülikoolist, Chapel Hill.
